Re: [PATCH v1] can: j1939: Fix UAF in j1939_sk_match_filter during setsockopt(SO_J1939_FILTER)

[Marc Kleine-Budde]

On 27.09.2023 18:14:56, Oleksij Rempel wrote:
> Lock jsk->sk to prevent UAF when setsockopt(..., SO_J1939_FILTER, ...)
> modifies jsk->filters while receiving packets.
> 
> Following trace was seen on affected system:
>  ==================================================================
>  BUG: KASAN: slab-use-after-free in j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
>  Read of size 4 at addr ffff888012144014 by task j1939/350
> 
>  CPU: 0 PID: 350 Comm: j1939 Tainted: G        W  OE      6.5.0-rc5 #1
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
>  Call Trace:
>   print_report+0xd3/0x620
>   ? kasan_complete_mode_report_info+0x7d/0x200
>   ? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
>   kasan_report+0xc2/0x100
>   ? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
>   __asan_load4+0x84/0xb0
>   j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
>   j1939_sk_recv+0x20b/0x320 [can_j1939]
>   ? __kasan_check_write+0x18/0x20
>   ? __pfx_j1939_sk_recv+0x10/0x10 [can_j1939]
>   ? j1939_simple_recv+0x69/0x280 [can_j1939]
>   ? j1939_ac_recv+0x5e/0x310 [can_j1939]
>   j1939_can_recv+0x43f/0x580 [can_j1939]
>   ? __pfx_j1939_can_recv+0x10/0x10 [can_j1939]
>   ? raw_rcv+0x42/0x3c0 [can_raw]
>   ? __pfx_j1939_can_recv+0x10/0x10 [can_j1939]
>   can_rcv_filter+0x11f/0x350 [can]
>   can_receive+0x12f/0x190 [can]
>   ? __pfx_can_rcv+0x10/0x10 [can]
>   can_rcv+0xdd/0x130 [can]
>   ? __pfx_can_rcv+0x10/0x10 [can]
>   __netif_receive_skb_one_core+0x13d/0x150
>   ? __pfx___netif_receive_skb_one_core+0x10/0x10
>   ? __kasan_check_write+0x18/0x20
>   ? _raw_spin_lock_irq+0x8c/0xe0
>   __netif_receive_skb+0x23/0xb0
>   process_backlog+0x107/0x260
>   __napi_poll+0x69/0x310
>   net_rx_action+0x2a1/0x580
>   ? __pfx_net_rx_action+0x10/0x10
>   ? __pfx__raw_spin_lock+0x10/0x10
>   ? handle_irq_event+0x7d/0xa0
>   __do_softirq+0xf3/0x3f8
>   do_softirq+0x53/0x80
>   </IRQ>
>   <TASK>
>   __local_bh_enable_ip+0x6e/0x70
>   netif_rx+0x16b/0x180
>   can_send+0x32b/0x520 [can]
>   ? __pfx_can_send+0x10/0x10 [can]
>   ? __check_object_size+0x299/0x410
>   raw_sendmsg+0x572/0x6d0 [can_raw]
>   ? __pfx_raw_sendmsg+0x10/0x10 [can_raw]
>   ? apparmor_socket_sendmsg+0x2f/0x40
>   ? __pfx_raw_sendmsg+0x10/0x10 [can_raw]
>   sock_sendmsg+0xef/0x100
>   sock_write_iter+0x162/0x220
>   ? __pfx_sock_write_iter+0x10/0x10
>   ? __rtnl_unlock+0x47/0x80
>   ? security_file_permission+0x54/0x320
>   vfs_write+0x6ba/0x750
>   ? __pfx_vfs_write+0x10/0x10
>   ? __fget_light+0x1ca/0x1f0
>   ? __rcu_read_unlock+0x5b/0x280
>   ksys_write+0x143/0x170
>   ? __pfx_ksys_write+0x10/0x10
>   ? __kasan_check_read+0x15/0x20
>   ? fpregs_assert_state_consistent+0x62/0x70
>   __x64_sys_write+0x47/0x60
>   do_syscall_64+0x60/0x90
>   ? do_syscall_64+0x6d/0x90
>   ? irqentry_exit+0x3f/0x50
>   ? exc_page_fault+0x79/0xf0
>   entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> 
>  Allocated by task 348:
>   kasan_save_stack+0x2a/0x50
>   kasan_set_track+0x29/0x40
>   kasan_save_alloc_info+0x1f/0x30
>   __kasan_kmalloc+0xb5/0xc0
>   __kmalloc_node_track_caller+0x67/0x160
>   j1939_sk_setsockopt+0x284/0x450 [can_j1939]
>   __sys_setsockopt+0x15c/0x2f0
>   __x64_sys_setsockopt+0x6b/0x80
>   do_syscall_64+0x60/0x90
>   entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> 
>  Freed by task 349:
>   kasan_save_stack+0x2a/0x50
>   kasan_set_track+0x29/0x40
>   kasan_save_free_info+0x2f/0x50
>   __kasan_slab_free+0x12e/0x1c0
>   __kmem_cache_free+0x1b9/0x380
>   kfree+0x7a/0x120
>   j1939_sk_setsockopt+0x3b2/0x450 [can_j1939]
>   __sys_setsockopt+0x15c/0x2f0
>   __x64_sys_setsockopt+0x6b/0x80
>   do_syscall_64+0x60/0x90
>   entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> 
> Fixes: 9d71dd0c70099 ("can: add support of SAE J1939 protocol")
> Reported-by: Sili Luo <rootlab@xxxxxxxxxx>
> Suggested-by: Sili Luo <rootlab@xxxxxxxxxx>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

Applied to linux-can/testing.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
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